Intumescent Coatings

ISOLATEK® Type WB 4 Intumescent Fire Resistive Material (IFRM)

ISOLATEK® Type WB 4 intumescent coating, when combined with ISOLATEK® Type Topseal, is the only water-based system investigated by Underwriters Laboratories (UL) for use in exterior applications.

It features the same distinct advantages of ISOLATEK® Type WB 3 which allows architects the ability to design using exposed steel structures that can be decorative and aesthetically pleasing.

ISOLATEK Type WB 4 can be top coated to match its surroundings which allow owners and designers the benefit of utilizing an environmentally friendly and visually appealing fireproofing method for steel structures which may be exposed to harsh exterior weather conditions.

Available in trowel grade, ISOLATEK Type WB 4 TG can be used for hard to reach areas or for repair applications.



  • The only water-based intumescent coating UL-classified for exterior applications.
  • Low VOC formulation; significant contribution to LEED certification.
  • Provides up to 4-hour fire resistance ratings in accordance with ANSI/ UL 263, ASTM E119, and CAN/ULC-S101.
  • The only UL-Classified Intumescent Coating with a Protected Floor Assembly rating.
  • Can be finished with a wide variety of approved topcoat finishes and colours.
  • Contains no harmful compounds.
  • Superior performance proven by wide range of testing.
  • Extremely durable, smooth architectural finish.
  • Water-based formula results in quick, easy application and clean up.

Product Uses

The only water-based intumescent coating UL-classified for exterior applications. Wherever an aesthetically pleasing, durable finish is desired on exposed steel beams, columns and floor decks utilized in a variety of open space projects including corporate headquarters, convention halls, atriums, retail facilities, hospitals, airports, rail and bus depots.

The first and only UL Classified Intumescent Fire Resistive Material (IFRM) with a “Protected” Floor Assembly rating (UL Design No. D601). This allows protected floor assemblies to remain exposed with a pleasant, paint-like finish.

Fire Tests & Approvals

In order to meet the performance and durability criteria set forth by the American Institute of Architects (AIA) and other major industry specifying organizations, CAFCO® SprayFilm® WB 4 has undergone the most rigorous testing in accordance with the world’s most demanding safety protocols.

UL 263, ASTM E119 - UL-263

Cellulosic – ANSI/UL263 (ASTM E119) – Fire Tests of Building Construction and Materials

This cellulosic fire test is traditionally used to evaluate materials for use in the protection of modern day commercial structures. This test reaches 537°C (1000°F) after 5 minutes and gradually reaches a temperature of 1093°C (2000°F) after a period of 4 hours.

ISOLATEK Type WB 4 is classified by Underwriters Laboratories for up to 4 hours protection on columns and 3 hours on beams and 3 hours on floor assemblies in accordance with the cellulosic fire test and is listed within various UL Designs.

UL Logo

UL Classification Mark

The UL Classification Mark indicates compliance with global requirements as it relates to a specific risk or casualty. With the Classification service, UL determines that a manufacturer has demonstrated the ability to produce a product complying with UL’s requirements with respect to one or more of the following:

  • Specific risk, e.g., casualty, fire, etc.
  • Performance under specific conditions
  • Compliance with regulatory codes
  • Compliance with specific standards such as international standards
  • Other condition, as determined by UL

All of the products carrying a UL Classification Mark are covered by UL’s Follow-Up Services program to verify that products carrying the UL Classification Mark continue to be manufactured in compliance with UL’s safety requirements.


New York City Materials and Equipment Acceptance (MEA)

An MEA Number is the number assigned to a product that has been approved for use in New York City by the MEA Division. ISOLATEK Type WB 4 (CAFCO SprayFilm WB 4 in the Americas) has been reviewed and MEA numbers have been assigned.

The MEA division regulates “certain materials and equipment (that) require Department of Buildings acceptance.” These manufactured items affect public safety, health and welfare (including structural stability and fire safety) and are usually a permanent part of a building.

Major Specification and Approval Compliance

ISOLATEK Type WB 4 complies with the requirements of the following specifications:

  • MasterSpec®, Section 078123 APPLIED FIREPROOFING (AIA)
  • MasterFormat® 2014, Section 07 81 00 Applied Fireproofing (CSC,CSI)
  • Unified Facilities Guide Specification, UFGS 07 81 00 Spray-Applied Fireproofing (USACE, NAVFAC, AFCEC, NASA)
  • Master Construction Specifications, Number 07 81 00 Applied Fireproofing (VA)
  • Code of Federal Regulations, Title 40 Protection of the Environment (EPA)
  • PBS-P100, Facilities Standards for the Public Buildings Services (GSA)

ASTM Physical Performance Standards  Test Performance*
Intumescent Fire Resistive Materials (IFRM’s)
Physical Property ASTM Standard ISOLATEK® Type WB 4
Surface Burning Characteristics ASTM E84 Flame Spread – 15
Smoke Developed – 0
Cohesion / Adhesion(Bond Strength) ASTM D4541 322 psi (2220 kPa)
Durometer Hardness ASTM D2240 81 Shore D
Impact Resistance ASTM D2794 98 inch-lb (10.85 Nm)
Abrasion Resistance ASTM D4060 0.2300 g/1000 cycles

*Based on independent laboratory tests under controlled conditions.